Use testharness.js instead of js-test.js in LayoutTests/fast/canvas tests.

third_party/WebKit/LayoutTests/fast/canvas/canvas-longlived-context.js

-description("This test ensures that Canvas and CanvasRenderingContext2D work correctly if the rendering context outlives the canvas element");
-
-function dataToArray(data) {
-    var result = new Array(data.length)
-    for (var i = 0; i < data.length; i++)
-        result[i] = data[i];
-    return result;
-}
-
-function getPixel(x, y) {
-    var data = context.getImageData(x,y,1,1);
-    if (!data) // getImageData failed, which should never happen
-        return [-1,-1,-1,-1];
-    return dataToArray(data.data);
-}
-
-function pixelShouldBe(x, y, colour) {
-    shouldBe("getPixel(" + [x, y] +")", "["+colour+"]");
-}
-
-function prepareCanvas() {
-    var context = document.createElement("canvas").getContext("2d");
-    context.fillStyle = "green";
-    context.fillRect(0,0,100,100);
-    return context;
-}
-
-function clobberGC(count) {
-    for (var i = 0; i < 5000; ++i)
-        ({a: i*i*i*0.5+"str", b: i/Math.sqrt(i)});
-    if (count > 0)
-        clobberGC(count-1);
-}
-
-function test() {
-    context = prepareCanvas();
-    clobberGC(40);
-    pixelShouldBe(50, 50, [0, 128, 0, 255]);
-}
-test();